Ping! while travelling?

Hey guys, just a question about how the Ping! app works when you travel outside of your local calling area (say overseas when travelling). The app advertises it is free for use internationally, but I assume that means if you live in Canada with an iPhone, you can Ping someone who lives in Finland with an iPhone for free. However go on a trip to France and want to Ping someone back home, you will incur international data roaming charges. Is this correct?